<!DOCTYPE html>
<html>
  <body>
    <div style="background: black;
                background-clip: padding-box;
                width: 400px;
                padding: 0;
                height: 300px;
                border: 100px solid rgba(255, 255, 0, 0.5);
                border-radius: 40.0%">
    </div>
  </body>
</html>
